A tan and white dog asleep on its side on a woven rug with its head resting on its front paws

October 12, 2026 Jessica Northrup

Crazy Dog Facts: Dreams, Noses, Eyes, Ears and Memory

Dogs dream, their noses are wet for a reason, and a reflective layer in their eyes helps them in dim light. These eight facts about dogs cover dreams, the wet nose, smell, night vision, hearing, laughter, emotions, and memory, and each one names the source that says it.

1. Dogs Do Dream

The AKC says scientists believe that dogs “not only dream as we do, but also that they dream similarly to us, meaning that they replay moments from their day while they’re fast asleep.” It adds that dogs “often bark or twitch their legs during REM sleep.”

The AKC reports that Stanley Coren advises watching a dog beginning about 10 to 20 minutes after it falls asleep: “If you can see their eyes moving behind their eyelids, they’ve begun to dream.”

Dogs can actually dream, and the AKC says that watching a dog dream “can be indicative of his breed.” It quotes Coren in Psychology Today: “Researchers found that a dreaming Pointer may immediately start searching for game and may even go on point, a sleeping Springer Spaniel may flush an imaginary bird in his dreams.”

A 2011 paper in the Journal of Small Animal Practice reports findings on 14 dogs with suspected rapid eye movement sleep behaviour disorder. The abstract says clinical signs “included episodes of violent limb movements, howling, barking, growling, chewing, or biting during sleep,” and that the disorder “is suspected to occur in dogs, as it does in human beings.”

2. A Wet Nose Helps A Dog's Sense Of Smell

Close-up of a dog's nose, showing the textured, moist skin around the nostril and the fur beside it

The AKC says wet noses work better: “Dogs depend on their highly developed sense of smell to interpret their world, and scent particles stick better to moist surfaces.” According to the AKC, the lining of a dog’s nose contains “special mucus-producing glands that keep his nasal passageways moist.”

The AKC also says the wet nose “cools your dog down on hot days, similar to how panting regulates his body temperature.” Dogs lick their noses on a regular basis, and the AKC says that “pups can also interpret smell through taste, thanks to a highly specialized olfactory organ called the Jacobson’s organ.”

3. A Dog's Nose Is Far More Sensitive Than Ours

The AKC says a dog’s nose is a hundred thousand times more sensitive than ours, at least. It also says: “When a dog sniffs, the structure of its snout lets it analyze odor molecules without exhaled air disturbing the scent trail.”

On the number of scent receptors, the AKC says humans have only 5 to 6 million in their noses, and that Bloodhounds “have 300 million.” It says dogs “can detect some smells in parts per trillion,” and gives an example: “You might smell chocolate chip cookies, but your dog can smell the chocolate chips, flour, eggs, and other ingredients.”

When dogs sniff each other, the AKC says: “They can detect the gender of the other dog, as well as clues to that dog’s age and health status.”

By detecting familiar scents, our pets can make more accurate decisions about what smells good and bad and thus increase their survivability! Caring for your dog’s specialized features is essential for their overall well-being. Ensuring they get the right nutrition and care is part of being a responsible owner, which is a philosophy we strongly believe in at HonestPet.

4. Dog Eyes Are Built For Dim Light And Fewer Colors

The AKC says that “when it comes to seeing in the dark, dogs definitely have us beat.” It credits two parts of the eye. The first is rods: “They are assisted by the high number of light-sensitive rods within the retina of their eyes. Rods gather dim light, which enables better night vision.” The second is the tapetum lucidum, “a special layer of reflective cells behind the retina that acts as a mirror within the eye, reflecting the light that enters it and giving the retina another opportunity to register that light.”

The tapetum also explains the glow in a dog’s eyes in a flashlight beam or a camera flash. The AKC says: “What you’re seeing comes from the tapetum.” It also says: “Some dogs, most commonly those with blue eyes, don’t have a tapetum.”

The same AKC page says: “Dogs see fewer colors than most humans (yellows and blues) and recognize objects only at much shorter distances.” It also says: “Dogs typically have 20/75 vision.” Pet parents who ask what do dogs see through their eyes can start with those lines.

A 2017 PLOS ONE study, High visual acuity revealed in dogs, trained whippets, pugs, and a Shetland sheepdog to tell patterns apart, and tested people in the same set-up. In dim light the dogs’ acuity ranged from 1.8 to 3.5 cycles per degree, and the people’s from 5.9 to 9.9. The authors write that “humans make visual discrimination of objects from roughly a threefold distance compared to dogs in both bright and dim light.”

5. Dogs Hear Sounds People Cannot

The AKC says the average adult human cannot hear sounds above 20,000 Hz, “although young children may hear slightly higher frequencies.” Of dogs, it says they “can hear sounds as high as 47,000 to 65,000 Hz.”

The AKC quotes Coren’s book How Dogs Think: “The truth of the matter is that, for some sounds, a dog’s hearing is really hundreds of times better than ours, whereas for other sounds, dogs and humans have sound sensitivities that are very much the same.”

Human hearing, the AKC says, “reaches peak sensitivity around 2,000 Hz,” and dogs have “maximum sensitivity around 8,000 Hz.” Humans hold an advantage in locating a sound: “People can detect a difference between two sounds that differ in location by an angle of only one degree. Dogs generally require about eight degrees of separation to distinguish where sounds are coming from.”

6. Dogs Laugh During Play

A cream-colored dog sitting on grass with its mouth open, looking up

The AKC says: “During play, dogs produce a vocalization that can be understood as laughter. This laughing vocalization is characterized as exhaling in a breathy way through their mouth.”

The AKC describes a study led by researcher Patricia Simonet that played a recording of dog-play vocalizations, including the laughing sound, to dogs at a Spokane shelter. The AKC says: “The scientists concluded that dog laughter could reduce stress behaviors among shelter dogs and even support dogs in initiating pro-social behaviors.”

7. Dogs Can Recognize Emotions

Studies support the idea that dogs can match a face to a voice. In a 2016 study in Biology Letters, “Dogs recognize dog and human emotions,” researchers showed dogs a human face or a dog face, happy or playful on one side and angry or aggressive on the other, while one vocalization played. The abstract says: “Dogs looked significantly longer at the face whose expression was congruent to the valence of vocalization.”

Its conclusion: “These results demonstrate that dogs can extract and integrate bimodal sensory emotional information, and discriminate between positive and negative emotions from both humans and dogs.”

8. Some Dogs Have Astonishing Memory

A 2011 study in Behavioural Processes tested one dog, Chaser, a border collie. The abstract says Chaser “learned and retained, over a 3-year period of intensive training, the proper-noun names of 1022 objects.” It says its fourth experiment showed Chaser’s “ability to learn words by inferential reasoning by exclusion,” which it describes as “inferring the name of an object based on its novelty among familiar objects that already had names.”

The study covers one dog. The AKC says Border Collies are “routinely on lists of the world’s smartest dog breeds.”

Positive reinforcement is how VCA says to train a dog: “The best way to train your pet is through the proper use of positive reinforcement and rewards while simultaneously avoiding punishment.”

Read more about dog training facts, or browse dog lover shirts from Animal Hearted.

Frequently Asked Questions On Crazy Dog Facts

Should I wake a dog that seems to be dreaming?

No. The AKC says to “follow the old adage ‘let sleeping dogs lie.’ Disrupting his sleep during the REM cycle can be startling (think about how you feel waking up from a dream), which can result in an unintended bite or, at the very least, a sleepy dog in the morning.”

Does a dry nose mean a dog is sick?

Not by itself. The AKC says there are “several perfectly normal reasons why a dog’s nose might be warm or dry, and it is worth noting that sick dogs can have wet noses, too.” It also says: “Most of the time, a dry nose is just a dry nose.” It says a dry nose is “sometimes a sign of an auto-immune disease.”

Can cats and dogs be friends?

Yes, often. The AKC says: “Cats and dogs are not natural enemies, but their instincts and communication styles can conflict. With proper introductions, supervision, and training, many pets learn to live together successfully.” It also warns that “large dog breeds with strong prey drives may injure cats, so keep safety in mind.”

Sources

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